As an electric powered vehicle configured to allow running by an electric motor using electric power from a vehicle-mounted power storage device typically represented by a secondary battery, there is known an electric car, a hybrid vehicle, a fuel cell vehicle or the like. An electric powered vehicle is generally configured having two types of power storage devices mounted, i.e. a power storage device of high voltage (for example, main battery) used to feed power to a traction motor, and a power storage device of low voltage (for example, auxiliary battery) used to feed power to an auxiliary machine including a control device.
In recent years, there has been developed an electric powered vehicle allowing a vehicle-mounted power storage device to be charged by a power supply external to the vehicle (hereinafter, also referred to as “external power supply”). For example, Japanese Patent Laying-Open No. 2009-27774 (PTL 1) discloses a configuration of an electric powered vehicle having the charging efficiency improved during an external charging mode.
Specifically, the electric powered vehicle of PTL 1 includes a main battery capable of being charged by an external power supply, a DC/DC converter down-converting the voltage of the main battery for output, and an auxiliary battery charged by the output voltage from the DC/DC converter. The DC/DC converter is operated continuously in a driving mode of the vehicle, and operated intermittently in an external charging mode. Accordingly, the power consumption by the DC/DC converter can be suppressed to improve the charging efficiency of external charging.